Wet nurses, women who breastfed others’ children for pay, have a venerable history, only going out of style when artificial infant formulas became widely available. Mothers who can’t nurse, but want their babies to have the nutritional and immune benefits of human milk now have more options than ever. These range from informal online networks of “raw” milk donors to Prolacta, a company that takes breast milk donations and sells an ultra-processed milk product for premature infants that costs thousands of dollars per baby per week.